PORT ARTHUR, Tex. — The National Transportation Safety Board blamed multiple corrosion cracks and “pervasive organizational failures” at the Calgary-based Enbridge pipeline company for a more-than-20,000-barrel oil spill two years ago near Michigan’s Kalamazoo River.
The cost of the spill has reached $800 million and is rising, the NTSB said, making the pipeline rupture the most expensive on-shore oil spill in U.S. history. The pipeline’s contents — heavy crude oil from Canada’s oil sands — have made the spill a closely watched case with implications for other pipelines carrying such crude.
The NTSB also blamed “weak federal regulations” by the Pipeline and Hazardous Materials Safety Administration for the accident, which spilled at least 843,444 gallons of oil into a tributary of the Kalamazoo in Marshall, Mich. The oil spread into a 40-mile stretch of the Kalamazoo and a nearby wetlands area.
The NTSB said Enbridge had noticed cracks as early as 2005 but had failed to repair them.